Lifting-jack.



PATENTED AUG. 21, 1906.

E. B. moms. LIFTING JACK.

APPLIUATIOH FILED MAR. 12, 1908.

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PATENTED AUG. 21, 1906.

E. E. THOMAS.

LIFTING JACK.

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Al/T/YEJJEJ lb -WW EDWIN E. THOMAS, OF PORTLAND, OREGON.

LlFTlNG"JACK- Specification of Letters Patent.

Patented Aug. 21, 1906.

Application filed March 12, 1906. Serial No. 305,481-

To all whom it may concern:

, Portland, county of Multnomah, Oregon,

have invented certain new and useful Improvements in Lifting-Jacks, ofwhich the ollowing is a specification.

Liftin -jacks as usually made must be placed c ose to the load to beraised, and oftentimes the lifting operation is attended with greatdanger to the life and limb of the operator, particularly when the loadis high and composed of lumber or of loose material. It has been foundalso very di'llicult to get down low enough to use an ordinary 'ack whenthe load is close to the ground. hen the load is wide or on a platform,the jack is located under the middle of it with a suitable cross-bar;but it is a diil'icult and dangerous operation to place the jack in thatposition. Sometimes two jacks are used, one on each side of the load andconnected with one another by a cross bar or beam. This, however, hasbeen found to be a laborious and tedious method of lifting a load.

The object, therefore, of my invention is to provide a lifting-jackcapable of use under various conditions and of very simple construction,having but few working parts and these being plainly exposed to view tofacilitate their adjustment and permit convenient inspection and repair.

further ob'ect is to provide a lifting-jack which will one 1c theoperator to stand at a safe distance from the load during the operationof raising it.

A further object is to rovide a jack which can be easily and quicliilylowered without danger of injuring the attendant.

Other obi'ects of the invention will appear from the fo lowing detaileddescription.

The invention consists, generally, in a base or bar normally stationarand a movable bar havin pivotal connections with the base and held inparallel relation therewith, said movable bar engaging the bottom of theload to be raised.

Further, the invention consists in providing the movable bar with a hookor step device whereby the preliminary raising of a low-down load may beeffected.

Further, the invention consists in various constructions andcombinations, all as hereinafter described, and particularly pointed outin the claims.

In the accompanying drawings, forming part of this specification, FigureI is a side elevation of a liftin '-jack embodying my invention, themovab 0 her being shown in its down position. Fig. 2 is a similar viewillustrating the jack in its raised )osition. Fig. 3 is a top view ofthe ark. view on the line a: a: of Fig. 2. Fig. 5 is a sectional view onthe line 2 2 of Fig. 2. Fig. 6 is a sectional view on the line y 1 ofFig. 2. Fig. 7 is a detail view of the mechanism for operating the jack.

In the drawings, 2 represents a base rail or bar having forward and reartrucks 3 and 4 pivoted thereon on each side of the bar. These trucks orwheels are of any suitable size and facilitate the movement of the jackfrom place to place. shoes may be provided, or the rail may be allowedto restdirectly upon and slide on the ground.

5 is a bar arranged above the bar 2.

6 is a lever pivoted at its upper end to the bar 5 near one end andhavingan antifriction-roller 7 at its lower end, which rolls on the edgeof the bar 2, the lever 6 being composed, irefcrably, of two parts orpieces, the ends 0 which lap the upper edge of the bar 2 and form guidesfor the wheel or roller thereon. A second lever 8 is pivoted at itslower end to the bar 2 beneath the pivot of the other lever on the bar5, and the up er end of the lever 8 has an antifrietion roller or wheel9, which engages the lower edge of the bar 5, being guided thereon bythe projecting forked end of the lever 8. The levers 6 and 8 areconnected with one another centrally by a ivot-pin 10. The bars 2 and 5are thus hcl in parallel relation with one another during the upward anddownward movement of the jack. The end of the bar 5 is provided with apivoted hook or step 11, which extends down below the level of thebase-rail of the jack and is ada uted to he slipped in under a timber orice which lies near the ground to enable the operator to impart apreliminary raising movement to the load preparato to slipping the bar 5beneath the same the load of course being blocked up to allow the jackto be lowered and the bar 5 inserted beneath the load. In some instancesthe movement of the hook may be suflicient to raise the load to thedesired height without utilizing the bar. The

Fig. 4 is a sectional In place of the trucks lever to be dropped and thedog 18 to engage hook, however, is intended as an ad'unct to the bar andmay be used in connection with it or not, as preferred. Its attachmentto the jack gives it a wider range of use than usually found inappliances of this kind.

On the rear end of the base-rail 2 a bar 12 is pivoted, having a seriesof ratchet-teeth 13, said bar projecting at its upper end through a slot14, provided in a head-block 15 on the bar 5, the ratchet-bar serving asa guide for the head-block in its vertical movement with the bar 5. Anoperating-lever 16 is pivoted at 17 on the block 15 and carries agravity-dog -18, pivoted at 19 thereon and havi a weighted handle 20,which normallg holds the dog in engagement with the ratchet-teeth 13. Aravity-do 21 is pivoted on the bar 5 and has a weig ted handle 22, whichholds the said dog in enga ement with the ratchet-teeth 13. Both 0%these dogs are ads ted to slip over the ratchetteeth when the bar 5 israised and lock the said bar a ainst downward movement. The lever 16when raised on its pivot will move the dog 18 over one or moreratchetteeth, according to the degree of movement of the lever, and thenwhen pressure is applied to. the outer end of the lever to force it downthe bar 5, whereon the short arm of the lever is mounted, will be liftedto raise the load. During the time the lever 16is being swung upward thedog 21 will remain in engagement with the ratchet-teeth and lock the bar5 against depression. In other words, the dog 18 will aetas a fulcrumfor the lever 16 during the raising of the bar 5, while the dog 21 willserve as a lock and relieve the lever 16 of the weight of the load andallow it to be oscillated easily to impart the upward ste -by-stemovement to the lifting-bar 5. he loa ma be anywhere along thehorizontal top of t e bar 5. The levers 6 and 8 will evenly distributethe strain, and it will be immaterial whether the load be upon the endof the lifti -bar or the middle ortion thereof. The loc in -dog 21 willsli e over the ratchet-teeth as t e bar 5 is raised tooth by tooth, andthere will be no danger of the load falling through accidental movementof the operating-lever.

When it is desired to lower the load, the operator will grasp the lever16 with one hand and raise the weighted handle 20 with the other hand,thus disengaging the dog from the ratchet-teeth. This will allow the alower tooth on the rack-bar. Then ear down on the lever Ifiuntil theload has been raised slightly and raise the handle 22, dieenga the dog2lfrom the ratchet. Then b sa ing the weight of the load to swing t elever 16 upward the dog 21 may be lowered one or two teeth, as desired.By reeatin the above-described 0 eration the ack with the load thereoncan e easily and quickly lowered to the desired level. .If for anyreason it is desired to drop the jack instantly to its lowest position,the lever 16 is raised to a point above the up er limit of its .normalstroke or until a beve ed surface 23 on the said lever engages a pin24on the block 15. When this occurs, the dog 18 will be automaticallydisengaged from the ratchet teeth, and u on lifting the handle 22 the do21 will also he disengaged and the jack wil drop by gravity to its deressed position. When it is desired to raise the jack to its elevatedposition without any load thereon, the

of the bar 5 shown in Fig. 1 and then when the timber is blocked thehook may be removed and the entire jack thrust under the timber, as alsoindicated in said figure, the dotted lines representin a stick of timberwhen first engaged by the lifting-hook, and then the same stick oftimber raised to a sufficient level to allow the bar 5 to be thrustbeneath it. I regard this lifting-hook as a useful adjunct to myinvention, but not an indispensable one, as the jack will be thorough ypracticable and a valuable device for handlin r lumber and othermaterial, even if the hool; is entirely omitted. I do not wish to beconfined either to the use of the wheels or trucks in connection withthis jack, as they may be omitted, if desired. In various ways also thedetails of the o crating mechanism may be modified wit out departingfrom my invention.

I claim as my invention 1. The combination with a base-bar, of alifting-bar, means connectin said base-bar and said liftin -bar, meansor raising and lowering said ifting-bar, and comprismg a ratchet-bar andlever and dogs carried by said lifting-bar and lever and means carriedby said liftin -bar and adapted to enga e the bottom of a cad below thelevel of sai ing-bar when in its depressed position, substantially asdescribed.

2. The combination with a base-bar, of a vertically movable lifting barsupported thereon, said lifting-bar being horizontal and movingvertically'in parallel relation with said base-bar, and aratchet-and-lever mechanism for raisin and lowering said liftingbar andmeans or trippin said mechanism 0 allow the quick depress on of saidlifting- 3. The combination with a base-bar havmg carrying-wheels, of alifting-bar, means connecting said base-bar with said lifting-bar lift-.ing pivoted at one end to one of said bars and havin anantii'riction-roller at the other end at apted to travel on the edge ofthe other bar, and a ratcl1et-and-lever mechanism for raising andlowering said lifting-bar.

5. The combination with a base-bar, of a vertically-moving lifting-barsupported thereon, a ratchet-bar mounted on said base-bar, a dogprovided on said lifting-bar and engaging the teeth of said ratchet, anoperating-lever pivoted on said lifting-bar, and a dog carried by saidoperating-lever and also engaging the teeth of said ratchet, and saiddogs normally locking said lifting-bar against depression, substantiallyas described.

6. The combination with a base-bar, of a vertically-moving liftingbarsupported thereon, a ratchet-bar pivoted on said base-bar and whereonsaid lifting-bar is vertically slidable, an operating-lever pivoted onsaid lifting-bar, a do carried by said operatinglever and engaging saidratchet-teeth, said dog having a beveled surface adapted to engage afixed pin provided on said lifting-bar when said lever is raised beyondthe normal limit of its upward movement, and a lockingdog carried bysaid lifting-bar and engaging the teeth of said ratchet, substantiallyas described 7. The combination, with a base-bar, of a verticallymovable liftin bar supported thereon, said li Fling-bar being horizontaland moving vertically in parallel relations with said base-bar and aratchet-and-lever mech anism having lifting and locking do s and meansfor tripping said. lifting-dog, w ereby upon disengagingosaidlocking-dog with one hand and raising said lever with the other, saidlifting-bar can be easily and quickly lowered, substantially asdescribed.

8. The combination, with a basebar, of a vertieally-mrwii1g lifting-barsupported thereon, a ratelwt-bar pivoted on said base-bar and whereonsaid lifting-bar is vertically slidable, an operating-lever pivoted onsaid lifting-bar, a dog carried by said operatinglever and engaging saidratchet-teeth, a lockingalog carried by said lifting-bar and alsoengaging the teeth of said ratchet, and means for automatically trippingsaid leverdog when said lever is near the limit of its upward movementwhereby upon raising said lever slightly and tripping said locking-dog,said lifting-bar can be easily and quickly lowered, substantially asdescribed.

In witness whereof I have hereunto set my hand this 20th day ofFebruary, 1906.

EDWIN E. THOMAS.

Witnesses F. G. DAVIS, ELIJAII Connmr.

